Wrapped entry box changed callback in try/except to handle ValueError

spirographs.py

@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 
+# Copyright 2021 Alexander Rowsell. Licenced under MPLv2.0
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
@@ -69,7 +70,11 @@ class spirographs:
         self.updatePlot()
 
     def bigRadiusEntry_changed_cb(self, widget):
-        self.bigRadius = float(widget.get_text())
+        try:
+            self.bigRadius = float(widget.get_text())
+        except ValueError:
+            print("Couldn't get a float for R, ignoring...\n")
+            return
         self.bigRadiusAdjustment.set_value(self.bigRadius)
 
     def smallRadiusAdjustment_value_changed_cb(self, widget):
@@ -79,7 +84,11 @@ class spirographs:
         self.updatePlot()
 
     def smallRadiusEntry_changed_cb(self, widget):
-        self.smallRadius = float(widget.get_text())
+        try:
+            self.smallRadius = float(widget.get_text())
+        except ValueError:
+            print("Couldn't get a float for r, ignoring...\n")
+            return
         self.smallRadiusAdjustment.set_value(self.smallRadius)
 
     def distanceAdjustment_value_changed_cb(self, widget):
@@ -89,7 +98,11 @@ class spirographs:
         self.updatePlot()
 
     def distanceEntry_changed_cb(self, widget):
-        self.distance = float(widget.get_text())
+        try:
+            self.distance = float(widget.get_text())
+        except ValueError:
+            print("Couldn't get a float for d, ignoring...\n")
+            return
         self.distanceAdjustment.set_value(self.distance)
 
     def recalcPoints(self):